Optical communication typically involves light transmitting information between two places. Information may be encoded or imprinted on the light via varying or modulating the light. So modulated, the light carries or conveys the information as the light propagates or travels from a sender to one or more recipients. Often, the modulated light follows a path laid out between the sender and the recipient; for example, one or more waveguides may guide the light towards its destination.
In many situations, a sender and a recipient desire to communicate more information than a single optical signal readily supports. One option for carrying additional information is to modulate the optical signal at a higher rate. However, elevating the modulation rate typically involves deploying more sophisticated systems and thereby incurring substantially higher cost. Further, as modulation rate increases, propagation over the waveguide may introduce signal distortion that complicates retrieving or discerning information from the optical signal. Accordingly, economics, engineering, application parameters, and/or physics can limit the amount of information that a single optical signal practically conveys.
To address this situation, conventional dense wavelength division multiplexing (“DWDM”) increases the information an optical waveguide carries via transmitting multiple optical signals over the waveguide. Typical of such conventional DWDM approaches, each optical signal is assigned exactly one narrow wavelength band, for example as set forth in the “ITU” specifications published by the International Telecommunication Union. A first DWDM signal may be assigned the optical spectrum of 1528.77-1529.16 nm, a second DWDM signal may be assigned the optical spectrum of 1529.55-1529.94 nm, a third DWDM signal may be assigned the optical spectrum of 1530.33-1530.72 nm, and so forth. Most conventional DWDM communication systems include sophisticated laser technology for keeping the optical signal in its assigned spectral band, and such technology can be expensive, cumbersome, or ill matched for certain applications. Further, conventional devices that multiplex or combine the DWDM optical signals for transmission or that demultiplex or segregate the DWDM optical signals for detection can be expensive, cumbersome, or ill matched for certain applications.
In view of the foregoing discussion of representative deficiencies in the art, need exists for improved technologies for transmitting more information over an optical path, link, or waveguide. Need is apparent for improved multiplexing systems and methods that may be implemented with reduced complexity, lower cost, increased manufacturability, relaxed tolerances, smaller size, better integration, less support equipment, more bandwidth, or other benefit, for example. A technology addressing any such need, or some other related shortcoming in the art, would promote high-speed optical communications and facilitate new applications.